Yes, both Travis CI and GitHub offer a Free Trial.
Travis CI is designed for Large Enterprises, Medium Business and Small Business.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for Travis CI Starts at $69/Month whereas for GitHub Starts at $4/User/Month.
Some top alternatives to Travis CI includes Codeship, Semaphore, GitLab, CircleCI, Bamboo, Buildkite, CloudBees Core, AppVeyor and GitlabRunner.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.